/Engine/Source/Runtime/Engine/Classes/GameFramework/AsyncActionHandleSaveGame.h
Schedule an async load of a specific slot.UGameplayStatics::AsyncLoadGameFromSlotis the native version of this. When the load has succeeded or failed, the completed pin is activated with success/failure and the newly loaded save game object if valid. Keep in mind that some platforms may not support trying to load and save at the same time.
static [UAsyncActionHandleSaveGame](API\Runtime\Engine\GameFramework\UAsyncActionHandleSaveGame) * AsyncLoadGameFromSlot ( [UObject](API\Runtime\CoreUObject\UObject\UObject) * WorldContextObject, const [FString](API\Runtime\Core\Containers\FString) & SlotName, const int32 UserIndex )